Boiler tube end-fitting assembly

ABSTRACT

A boiler tube end-fitting assembly wherein a threaded sleeve is adapted to be slidably mounted on each end of a boiler tube and soldered or brazed thereto, one of the sleeves having a flange adapted to abut the inner face of one end plate of the boiler, the other sleeve having a collar threadably mounted thereon and adapted to abut the inner face of the opposite end plate of the boiler, the threaded sleeves extending through the boiler end plates and secured thereto by washer and nut assemblies tightened against gaskets provided on the outer faces of the boiler end plates.

United States Patent 1 Johnson [4 1 July 24,1973

[ BOILER TUBE END-FITTING ASSEMBLY Clarence S. Johnson, PO. Box 940, Pomona, Calif. 91769 [76] Inventor:

[52] U.S. Cl. 122/511, 285/201 [51] Int. Cl. F22b 37/10 [58] Field of Search 125/511; 285/201 [56] References Cited UNITED STATES PATENTS 500,733 7/1893 Ashley 122/511 718,609 1/1903 Drake 122/511 972,164 10/1910 Crozier 122/511 756,246 4/1904 Lee 122/511 693,298 2/1902 Middleton... 122/511 254,731 3/1882 Trout 285/201 891,783 6/1908 Parkinson 122/511 Primary Examiner-l(enneth W. Sprague Attorney -Rupert J. Brady, James G. OBoyle et al.

[ 1 ABSTRACT A boiler tube end-fitting assembly wherein a threaded sleeve is adapted to be slidably mounted on each end of a boiler tube and soldered or brazed thereto, one of the sleeves having a flange adapted to abut the inner face of one end plate of the boiler, the other sleeve having a collar threadably mounted thereon and adapted to abut the inner face of the opposite end plate of the boiler, the threaded sleeves extending through the boiler end plates and secured thereto by washer and nut assemblies tightened against gaskets provided on the outer faces of the boiler end plates.

3 Claims, 5 Drawing Figures 1 BOILER TUBE END-FITTING ASSEMBLY BACKGROUND OF THE INVENTION Boiler tubes are conventionally secured to the boiler end plates by an expanded-tube method wherein a shoulder is formed on the tube by inserting a special tool into the tube and expanding the tube from the inside whereby the shoulder provides a stop to limit the projection of the boiler tube through the end plate; the end portion of the tube which protrudes through the end plate is then rolled or expanded against the outer face of the end plate to thereby secure the tube to the end plate. To replace or repair the boiler tubes in installations employing the expanded tube method of securing the tubes to the boiler end plates, requires the skill of a pipe fitter or boiler tender having experience well beyond that of an ordinary mechanic.

In order to overcome the disadvantages experienced in installations employing the expanded tube method of securing the boiler tubes to the boiler end plates which requires the skill of experienced pipe fitters employing special tools, the tube end-fitting of the present invention has been devised wherein a threaded sleeve is slidably mounted on each end of the boiler tube and soldered or brazed thereto, one of the sleeves having a flange formed thereon adapted to abut the inner face of one end plate of the boiler, the other sleeve having a collar threadably mounted thereon and adapted to abut the inner face of the opposite end plate of the boiler, the threaded sleeves extending through the boiler end plates and secured thereto by washer and nut assemblies tightened against gaskets provided on the outer faces of the boiler end plates.

BRIEF DESCRIPTION OF THE DRAWINGS headers;

FIG. 2 is an exploded view, partly in section, of the boiler tube end-fittings of the present invention; and

FIGS. 3, 4 and 5 are diagrammatic views illustrating the method of mounting the boiler tubes, employing the end-fittings of the present invention, between the headers.

Referring to the drawings and more particularly to FIG. 1, a finned tube 1 is shown mounted between the front header 2 and rear header 3 of a water-tube boiler 4, each end of the tube being respectively secured to the boiler end plates 5 and 6 by means of the endfittings of the present invention designated generally by the reference numerals 7 and 8.

The details of the construction of the end fittings are illustrated in FIG. 2 wherein it will be seen that the fitting 7 comprises a threaded sleeve 9 slidably mounted on the tube 1 and positioned so that the ends of the tube and sleeve are flush with each other, the flush ends being welded, soldered or brazed as at 10 to thereby rigidly secure the sleeve to the tube while maintaining the joint therebetween water-tight. The sleeve 9 is formed with a flange 11 adapted to abut the inner face of the boiler end plate 5 (FIG. 1), the sleeve extending through the end plate 5 and secured thereto by a nut 12 threadably mounted on the outer end of the sleeve and tightened against a washer 13 abutting a gasket 14 disposed on the outer face of the boiler end plate 5.

The end-fitting 8 comprises a threaded sleeve 15 slidably mounted on the end portion of the tube 1 and positioned with respect to the tube in a manner similar to sleeve 9; that is, the ends of the sleeve and tube are flush with each other and soldered or brazed as at 16 to not only rigidly secure the sleeve to the tube but also to provide a water-tight joint therebetween. A collar 17 is threadably mounted on the sleeve, the collar being adapted to abut the inner face of the boiler end plate 6 through which the sleeve 15 extends, the sleeve being secured to the end plate 6 by a nut 18 threadably mounted on the outer end of the sleeve and tightened against a washer 19 abutting a gasket 20 disposed on the outer face of the boiler end plate 6.

The manner of installing the boiler tube is illustrated in FIGS. 3 to 5 wherein it will be seen that the collar 17 is threaded to the innermost position on sleeve 15 which is inserted through the end plate 6 thereby aligning the sleeve 9 on the opposite end of the tube with the aperture 5a formed in the boiler end plate 5. The tube 1 is then shifted to the left as viewed in FIG. 4 thereby inserting the sleeve 9 through the aperture 5a until the flange 11 abuts the inner face of the boiler end plate. The collar 17 is threaded outwardly of the tube until it abuts the inner face of the boiler end plate 6, the assembly then being tightened to a water-tight condition by means of the nuts'12 and 18, and associated washers, secured to the outer ends of the tubes and abutting the outer faces of the boiler end plates 5 and 6, respectively.

From the above description, it will be readily appreciated by those skilled in the art that the end-fittings of the present invention provide an improved assembly for the installation of tubes in a boiler wherein the removal and installation of the tubes can be accomplished by a relatively unskilled workman employing conventional tools.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

I claim:

1. An end-fitting assembly for mounting a tube between the front and rear headers of a water-tube boiler comprising, sleeve means mounted on each end of said tube, each sleeve means extending through a respective header plate on each end of said boiler, a flange formed on one of the sleeve means, said flange being adapted to abut the inner face of one of the boiler header end plates, a collar threadably mounted on the other sleeve means and being adapted to abut the inner face of the opposite boiler header end plate, and nut means threaded on the outer end portions of said sleeves for securing said tube to said boiler header end'plates.

2. An end-fitting assembly according to claim 1 wherein each sleeve means is slidably mounted on said tube, the ends of the sleeve means being flush with the respective ends of the tube, the sleeve means being welded to the tube at the ends thereof to thereby rigidly secure the sleeve means to the tube and to render the joint therebetween water-tight.

3. An end-fitting according to claim 1 wherein washers are mounted on the sleeve means at each end of said tube and abut gaskets disposed on the outer face of each header end plate, said'washers being tightened thereagainst by said nut means to secure the end-fitting assembly between said headers and to seal said tube ends within said boiler headers.

* I l =lt 

1. An end-fitting assembly for mounting a tube between the front and rear headers of a water-tube boiler comprising, sleeve means mounted on each end of said tube, each sleeve means extending through a respective header plate on each end of said boiler, a flange formed on one of the sleeve means, said flange being adapted to abut the inner face of one of the boiler header end plates, a collar threadably mounted on the other sleeve means and being adapted to abut the inner face of the opposite boiler header end plate, and nut means threaded on the outer end portions of said sleeves for securing said tube to said boiler header end plates.
 2. An end-fitting assembly according to claim 1 wherein each sleeve means is slidably mounted on said tube, the ends of the sleeve means being flush with the respective ends of the tube, the sleeve means being welded to the tube at the ends thereof to thereby rigidly secure the sleeve means to the tube and to render the joint therebetween water-tight.
 3. An end-fitting according to claim 1 wherein washers are mounted on the sleeve means at each end of said tube and abut gaskets disposed on the outer face of each header end plate, said washers being tightened thereagainst by said nut means to secure the end-fitting assembly between said headers and to seal said tube ends within said boiler headers. 